As a hobby, smoking is very popular with people, especially men. However, tar in cigarette is harmful to human health, and dozens of compositions thereof are carcinogens. Besides, secondhand smoke does a great harm to non-smokers. Therefore, there is a regulation to prohibit smoking in most of public places. However, it is very difficult for a smoker not to smoke. Accordingly, electronic cigarettes, used as substitutes for conventional tobaccos, have been widely used.
As shown in FIG. 1, in an existing electronic cigarette, an inlet channel is defined in a casing of the electronic cigarette. External gas enters the electronic cigarette through the inlet channel, further flows into a recess defined at the bottom end of an upper electrode, and finally flows into atomization channel and brings atomized smoke to the suction nozzle for the smoker to suck in. The arrow direction shown in FIG. 1 directs to a gas flowing direction. It can be seen from the figure that, after the external gas enters the electronic cigarette, the gas needs to make a couple of 90 degree turns before entering the atomization channel. In this way, the gas flow changes strongly, and the flow path of the gas is long since the gas needs to flow from the inlet channel to the bottom end of the upper electrode. Besides, a lot of noises may be produced when the smoker is smoking, and thus the user experience is affected.